Lage krachtvoergiften en diergezondheid in de biologische melkveehouderij

Organic dairy farmers have multiple reasons to choose a farm strategy with low concentrate input per unit of milk produced. First and foremost, concentrates and concentrate replacers of organic origin are expensive. Therefore, depending on the milk prices, concentrate feeding is often uneconomical. Some organic farmers have ideological reasons for a low concentrate input, they want to minimize the human food for animal feed competition as much as possible. Whereas in other situations, there is simply a lack of locally or regionally produced organic concentrates. Low concentrate inputs likely result in a reduced energy intake, thereby increasing the risk of a more severe negative energy balance (NEB) in high producing dairy cows. In the literature, a severe NEB is associated with metabolic disorders (e.g. ketosis, fatty liver), reduced fertility, immune suppression, and production diseases. These problems suggest that cows at dairy farms with a low concentrate input strategy (LCI) are probably at a greater risk for diseases associated with an NEB. However, this suggestion has not been verified with data from commercial organic farms. Therefore, a field study was conducted to investigate the farm management strategies, roughage quality, milk production, body condition score, animal health on organic farms that use a low concentrate input strategy (LCI) and to compare these data with other organic farms. The data were obtained from the “Weerstand” database, which contains information on farm characteristics, milk production, animal health, concentrate input, roughage quality, diets and body condition score (BCS) from 100 organic farms in the Netherlands. In our study, a farm was defined as a low concentrate input (LCI) farm when the concentrate input was less than 12 kg/100 kg milk produced. There were fifteen farms from the Weerstand database that met the definition of a LCI farm. These LCI farms were compared with a remainder group of other organic farms (OOF). Milk production on LCI was 6979 kg in 355 days, which was 750 kg lower than on OOF. The cows on LCI had a lower peak production (=3.5 kg/day), and a more persistent lactation curve. On both LCI and OOF, the cows were predominantly Holstein=Friesian. However, LCI farms had slightly more dual purpose breeds. The average BCS was slightly higher on LCI than on OOF. The LCI farms rely more on grazing, which resulted in a more seasonal= based production system with relatively more spring calving cows. The farm types did not different in the incidence of metabolic diseases and fertility rates, but LCI farms had slightly higher somatic cell count (20000 cells). The data indicate that a low concentrate input system on organic dairy farms does not necessarily result in more severe NEB or reduced animal health and fertility. The cows on LCI farms had a clearly lower peak yield and more persistent lactation curve. However, it is not clear if this is the result of feeding strategy or purposive selection and breeding. Further research on the effect of peak yield and persistency of the lactation curve should be initiate

Lage krachtvoergift hoeft niet te leiden tot meer gezondheidsproblemen

In de biologische melkveehouderij zijn er tal van bedrijven die om economische of ideële redenen weinig krachtvoer geven. Dit leidt tot een lagere energieopname en een verhoogde kans op een ernstige negatieve energiebalans (NEB). Een ernstige NEB wordt in verband gebracht met stofwisselingziekten en verminderde immuniteit. Uit onderzoek blijkt dat een bedrijfssysteem met een lage krachtvoergift niet hoeft te leiden tot meer problemen met diergezondheid en vruchtbaarheid die worden gerelateerd aan een NEB

The development of a model for the prediction of feed intake and energy partitioning in dairy cows

Balancing the supply of on-farm grown forages with the production targets of the dairy herd is a crucial aspect of the management of a dairy farm. Models which provides a rapid insight of the impact of the ration, feed quality and feeding management on feed intake and performance of dairy cows are indispensable to optimize feeding strategies, allocation of feeds and purchased concentrates, in order to find the best compromise between milk performance, nutrient use efficiency, manure excretion, gaseous emissions and profitability. This thesis describes the development of the Wageningen UR Dairy Cow Model (Wageningen DCM), a model for the prediction of feed intake and performance of dairy cows. The Wageningen DCM is constructed from two modules: a feed intake model and an energy partitioning model which describes the partitioning of the ingested net energy to milk energy output and body reserves. For the development of the feed intake model a calibration dataset was compiled with 38515 weekly records of ration feed composition, diet composition, individual feed intakes, milk yield and composition, parity, days in lactation and days pregnant from 1507 cows. The feed intake model predicts dry matter intake (DMI) from feed and animal characteristics. Data of standard feed analysis were used to estimate the satiety value (SV) of numerous feeds. The SV is the measure of the extent to which a feed limits intake. The cows’ ability to process the intake-limiting satiety value-units is expressed as the feed intake capacity (FIC). The FIC is estimated from parity, days in milk and days of pregnancy which are indicators of the size and physiological state of the cow. An evaluation of the feed intake model was performed using an independent dataset containing 8974 weekly means of DMI from 348 cows. On the basis of mean square prediction error (MSPE) and relative prediction error (RPE) as criteria, it was concluded that feed intake model was robust and can be applied to various diets and feeding management situations in lactating HF cows. A second model was developed to predict the partitioning of ingested net energy (NEL) to milk energy and body reserves. This energy partitioning model describes the baselines of daily NEL intake and milk energy output (MEO) during successive lactation cycles of a ‘reference’ cow. The MEO and change in body energy of a cow is estimated from deviation of NEL intake from the baseline. A NEL intake above the baselines results in a higher predicted MEO and reduced mobilization of body energy reserves. Whereas, a NEL intake below the baseline results in a lower predicted MEO and increased mobilization. The proportion of ingested NEL partitioned to MEO depends parity number, days in lactation and pregnant, reflecting the changes in priority in energy partitioning during successive lactation cycles of a dairy cow The feed intake model and energy partitioning model are integrated in the Wageningen DCM. Model simulations showed that the Wageningen DCM is able to simulate the effects of diet composition, nutritional strategies and effects of cow characteristics (parity, days in milk and pregnancy) on dry matter and nutrient intake, and the partitioning of ingested NEL into MEO and body energy. The Wageningen DCM requires easily available input data. Validation of the Wageningen DCM with external data indicated a good accuracy of the prediction of intake and milk energy output with relatively low prediction errors ≤ 0.1. The Wageningen DCM enables users to analyse and compare different feeding strategies, identify limitations of feeding strategies, formulate diets, calculate feed budgets and to develop economic and environmental sustainable feeding strategies.</p

Efficiënt gebruik van snijmaïs. Deel 5: invloed afrijpingstype en oogststadium op opname en melkproductie = Efficient use of silage maize. Part 5: effect of maturity type and harvest stage on intake and milkproduction

In the period 2003-2005 effects of genotypes and maturity stage on yield, quality, conservation and nutrition have been investigated. This research was focusing on the effects of maturity type and energy type on intake and milk performance. There was no influence of maturity type (stay green and dry down) on intake and milk performance. The starch energy type caused a higher milk performance than the cell wall energy typ

Gevolgen en perspectief van regionaal voercentrum voor de melkveehouderij = Implications and perspective of regional feed centre for the dairy sector

The implications of a regional feedcentre for environment, society and regional innovations are given. Perspective for coöperation between dairy and arable farmers for different regions in the Netherlands is shown

Benutting van herfstgras op veengrond door melkkoeien

On peat soils, milk production of autumn grazed dairy cows is often disappointing. Reduced palatability (i.e. a musty smell) of autumn grazed grass and consequently a reduced intake is considered as the main reason for the decline in milk production. A grazing experiment was conducted to compare 3 different strategies of grassland management within a rotational grazing system to improve the utilisation of autumn grazed grass by dairy cows for milk production. In the experiment, 36 mid-lactation dairy cows were used to form 3 balanced groups (“control”, “rationed” and “clean”) of 12 cows each. For all strategies, the grass cover was aimed at approximately 1500 kg DM/ha (rising plate meter sward height of 16 to 18 cm) at the moment of turning into the paddock

Sturing melkureumgehalte op dierniveau via de voeding

Het Praktijkonderzoek Veehouderij voerde in de winterseizoenen van 1997-1998 en 1998-1999 een viertal voederproeven uit die antwoord moesten geven op de vraag of er variatie bestaat in het optimale melkureumgehalte tussen individuele dieren en in welke mate het melkureumgehalte van individuele dieren valt te sturen door middel van de voeding

"Graasvisie" helpt bij beweidings management

Graasvisie is een nieuw hulpmiddel voor het krijgen van inzicht in de effecten van beweidingsmanagement. Het programma kan door melkveehouders en adviseurs worden gebruikt bij bijvoorbeeld de keuze van een optimaal beweidingssysteem. Graasvisie is ontwikkeld door Wageningen UR Livestock Research en te vinden op: www.livestockresearch.wur.nl/NL/onderzoek/Producten_en_diensten/Software. Het programma is reeds ingezet bij adviseurs van de Stichting weidegang